An indirect method for the determination of liquid hold-up was proposed. The method is based on the fluidized droplets model of packed column flooding and was used to determine the liquid hold-up in packed columns working with vapour pulsation. The results point to the liquid hold-up as the main factor contributing to the increase of the mass transfer rate in pulse columns. The dependence of liquid hold-up on the frequency and amplitude of pulsation suggests that packed pulse columns might be used in reactive distillation.